First on the list as an 18-year-old in 1962 after graduating from the Fourths, Jacobs made his senior league debut two seasons later and played in a premiership in just his 16th game. The centre-half forward/forward pocket had kicked more than two goals a game for the year, including an equal career best haul of five against South Melbourne, and had also played as a ruckman in the forward line.

He followed up this early success with 14 more games in 1965, before suffering an achilles injury late that year that affected him into the next season. He returned in Round 2, 1966 but it was his only match for the season as he battled an ankle injury.

Jacobs improved to five matches in 1967 but along with Terry Leahy was dismissed by the Demons at the end of that year as a "disciplinary measure" after a trip to Queensland, and despite being linked to Carlton moved to South Melbourne for three years of regular football before being delisted by the Swans at the end of 1970.

After his VFL career ended Jacobs played with Mitcham for four seasons - coaching them in 1972. He also coached two premierships in a five year stint at Vermont, and coached at Bulleen-Templestowe and Ringwood East.